Network & Logging In Software

Hi my rig is the router and “server,” I am using microsofts networking, however i find that it is too simplisitc i was wondering what program shoul i use, because i need ICS for sharing the interent to others at my crib, however i want to share my hard-drives resources but not allow them to gain access without logging in…I was think of novell but its complex i want something simple…
I was wondering what software can i use to create a login to gain access to certain folders?